A blog created to share information from Local Care Midwifery, PLLC with women and families of New York's Capital District and beyond.

Saturday, April 30, 2011

There is so much to celebrate this week-finally we have spring weather; International Midwife's Day is Thursday, May 5; Mother's Day is next Sunday; Cody's 18th birthday is May 4th (that's my baby); LCM's first Mom's et al group meeting is this Wednesday; International Workers Day is this Sunday, May Day. Come celebrate them all with us this Sunday, May 1 from 1-6. Stop in any time for a quick hug and a cookie, or for a long chat and time with friends.

Wednesday, April 27, 2011

It's often said that it takes a village to raise a child, but due to the increasingly fragmented nature of modern society, too many women and families are cut off from the roots from which to draw strength, friendship and support.

Enter the LCM Moms Group, graciously organized by the ever fabulous Jillian. Jillian is a new mom living in Troy, and Michelle was her midwife when her son was born in March. We are interested in starting an inter-generational Moms Group. We'd like to create a space for community building: a place where women can get to know other women, and where kids are welcome (and safe) to run around. We hope that this will be a helpful resource to the wonderful families of the Capital District whom we are honored to serve.

What: The first meeting of the Local Care Midwifery Moms Group
When: Wednesday, May 4, 2011 -- 10:00am to 12:00pm
Where: St. Paul's Episcopal Church, Guild House, 27 State St, Troy, NY 12180 (Note: Guild House is also called Bethany House and is directly behind St Paul's which is on the corner of 3rd Street and State)The Extra Information:

Although childbirth is something that unites all and is the throughline of our gathering, it isn't necessarily the only focus. For instance, the Moms Group seems like a great opportunity to start monthly meal swaps--not to mention perhaps donating meals to moms in the group who give birth throughout the year.

It's my vision that a different woman would lead each meeting with a focus on something she does well and wants to share with us or wants to know more about. Of course, at our first meeting, I'd like to assess what the group of moms as a whole is truly interested in doing and proceeding accordingly.

We hope to see you there!

DON'T FORGET! THE LOCAL CARE MIDWIFERY, PLLC OPEN HOUSE AND SPRING SHOWER IS THIS SUNDAY, MAY 1ST FROM 1-6PM! WE HOPE TO SEE YOU THERE!

Tuesday, April 19, 2011

Strange but true -Saturday April 22 2011 at 12:00 EST, people all over the world will simultaneously change their child's cloth diaper, The Great Cloth Diaper Change. SonRise Diaper Service and Diaper Envy have joined up to bring this Guinness Book of World Records Event to the NY Capital District. Come and join us for fun family friendly events (even if you aren't signed up and don't plan on changing a diaper). There will be a variety of activities including a DYI workshop on recycling a wool sweater into a diaper cover and yoga for kids. Local Care Midwifery plans to be there to join in the fun. Come and play this Saturday. Come early (10:00) and join in the church's Easter Egg hunt.

Monday, April 18, 2011

Many of you have seen the wonderful e-newsletter that Local Care Midwifery just launched. But for anyone we missed, please take a look and sign up so the next copy will come straight to your in-box. Johanna Holmes, our Web Gura did her usual fabulous job on the newslettter. Thank you Johanna. And special thanks to Nicole for sharing her birth story with us and the entire virtual world.

Wednesday, April 13, 2011

Our very own Lisa Bruchac is the Featured Mom for In Season Mom. The website is for first time moms over age 35. It has been a big support to Lisa in her parenting journey. Thank you for letting us be part of that journey too!

Current or former profession(s): Speech Pathologist; certified health and wellness coach

PREGNANCY

InSeason Mom: How long were you trying to get pregnant?

Lisa: Several months

InSeason Mom: What did you do or not do to increase your chances of getting pregnant after 35?

Lisa: After several months of trying to conceive, I got pregnant only to miscarry at 5 weeks. At that point, I started going to a nutritionist to cleanse and balance my system to achieve a baby-ready-body. I also did some energy clearing work to make sure there weren’t any subconscious beliefs blocking me from becoming pregnant. We stopped “trying” to get pregnant for several more months until I felt like my body was ready. I got pregnant in the fourth month when we started trying again.

SUPPORT

The Medical Community

InSeason Mom: How supportive were your doctors during your pregnancy? Were you surprised by their reaction? Did you change doctors or would like to have changed doctors? Why or why not?

Lisa: I started my pregnancy in a traditional OB-GYN medical practice. What surprised me the most about my visits was the way I did not feel listened to. I felt they pushed their agenda onto me and expected me to go along with their ideas. I even had the office manager call and confirm an appointment with a genetic specialist and I didn’t even know the office had scheduled one. I declined and had to explain to the nurse practitioner why. I did not feel comfortable when constantly bombarded with all the risks involved with having a baby over 40.

The other issue was that I saw only the nurse practitioner at every appointment and she didn’t even deliver so I wasn’t able to have any of my questions about the actual birth answered. I had one brief appointment with the practice’s midwife and was again pressured to have certain tests done. I didn’t want to make any decisions based on fear. So I had to continually tune out the external stimuli in order to go within and make decisions based on what I really needed or wanted.

Finally, at 5 months pregnant and frustrated, I spoke with a midwife in my town who suggested a home birth. I was a little skeptical, but thought we should at least meet with the midwife she recommended. My husband and I met with her for over an hour and were very pleased with her calm demeanor and attitude toward childbirth. She provided information in a way that allowed me to make my own decisions. It was more of a partnership than the traditional doctor-patient relationship. Once I switched, my pregnancy was so much calmer and I worried less.

Family and Friends

InSeason Mom: Who was the first person you told about your pregnancy and why?

Lisa: I couldn’t wait to tell my husband. I handed him the positive pregnancy test.

InSeason Mom: What was the reaction of friends and family when you told them about your pregnancy?

Lisa: They were very excited.

LABOR AND DELIVERY

InSeason Mom: Did you take any childbirth classes? Why or why not?

Lisa: No. I read a lot of books. I didn’t feel that a lot of the birthing classes focused on natural childbirth or the mind-body-spirit connection. The whole experience to me was very spiritual and I read a lot of books that focused on that aspect.

InSeason Mom: Where did you give birth?

Lisa: At home with my husband, midwife and doula.

InSeason Mom: What do you remember most about the birth experience?

Lisa: I remember all of it. Labor was intense and I didn’t progress as quickly as I would have liked. But in the end, both my baby girl and I were safe and healthy. And when she was placed on my chest, I felt an incredible surge of love and vulnerability. It was truly amazing.

I AM A MOM

InSeason Mom: What concerns you most about being a mom over 35 and how do you compensate for this fear?

Lisa: The fears that have come up for me have to do with worrying about how old I’ll be when she’s a certain age. I would constantly think, “When she’s 10 I’ll be 52 or when I’m 60 she’ll be 18”. I had to let that go. She’s an inspiration to me to stay healthy and active. So now I focus on those things that I can control.

InSeason Mom: What do you enjoy most about being an older mom?

Lisa: The time I get to spend with her. My priorities are very different from when I was in my 20’s or 30’s. I am also more confident in who I am at this age and how I want to raise her.

InSeason Mom: How has becoming a mom changed you?

Lisa: It’s been an amazing healing for me. She has taught me so much. She brings me back to the present moment so often I find myself staying there longer than I used to.

InSeason Mom: What advice do you have for women considering motherhood after 35?

Lisa: Be as healthy as you can be. Make healthy choices to eat right and exercise. Don’t overlook emotional healing work as well. There is definitely a connection between mind-body-spirit. And I believe this can impact fertility at any age.

InSeason Mom: Any additional comments?

Lisa: I highly recommend interviewing your potential caregivers. I believe it is so important to be comfortable and validated. I believe in listening to ones own heart when making decisions, but having the right information presented in a gentle and unbiased way is crucial.

InSeason Mom would like to thank Lisa for being an inspiration to moms across the world! If you are a first time mom over 35 and would like share your story, please email me: cynthia@inseasonmom.org

Thursday, April 7, 2011

"Birth is not only about making babies. Birth is about making mothers--strong, competent, capable mothers who trust themselves and know their inner strength." Barbara Katz Rothman

For each woman, and each birth, there is a story to tell. No matter how long or how short a labor, how challenging, ecstatic, demanding or blissful a birth is, each birth is the setting where a woman crosses the threshold into mothering an unique and irreplaceable child, making that journey by her own efforts and her own choice. Birth is fundamentally a gift that only a mother can give, and when a woman tells her story of her experience giving birth, we all benefit from being able to witness her courage and wisdom. Writing a birth story is a beautiful way to share the story of your child's birth, as well as a way to honor your experience as a woman and a mother.

We know that trying to write a birth story can feel overwhelming, but here are a few tips to make it easier:

Write when you are ready to write: don’t try to force a story that you aren’t fully ready to tell yet. There is no time frame in which you “have to” write your story, and some may take longer than others.

Focus primarily on what was important and meaningful to you, and don’t worry if you forget some things in the process. A story doesn’t have to have every single small detail included in order to be true.

Be as creative as you want to be! If your birth story is best told in a poem, in a piece of artwork, a song, be true to yourself and honor your experience through whatever medium it best shines through.

We are starting to get our first birth stories in, and are grateful to have been able to support so many strong women as they meet their children for the first time face to face. We invite all of our clients to share their birth stories with us, and hope to grow from the wisdom they contain. If you want to write your birth story but need some help through the process, a professional writer/editor is available to offer whatever help you need.

Wednesday, April 6, 2011

The meta-analysis by Wax published by ACOG last year is being shown to be exactly what it initially appeared to be -deeply flawed. This articles' conclusions sums up the situation perfectly, " The debate over the safety of home birth is deeply divided and emotionally charged. Reliable information is required to allow productive debate and informed decisions. In an era of evidence-based medicine, it is incomprehensible that medical society opinion can be formulated on research that does not hold to the most basic standards of methodological rigor." Here's to evidence, diligent researchers and families that continually press for the truth.

Saraswathi Vedam, SciD

Associate Professor & Director, Division of Midwifery, University of British Columbia, Vancouver, British Columbia; Senior Consultant, Division of Research, Midwives Alliance of North America, Washington, DC; Chair, Home Birth Section, Division of Standards and Practice, American College of Nurse-Midwives, Silver Spring, Maryland

A Flawed Analysis

The highly charged debate over the safety of home birth was inflamed by the publication of a meta-analysis by Joseph R. Wax and coworkers,[1] which concluded that "less medical intervention during planned home birth is associated with a tripling of the neonatal mortality rate." The statistical analysis upon which this conclusion was based was deeply flawed, containing many numerical errors, improper inclusion and exclusion of studies, mischaracterization of cited works, and logical impossibilities. In addition, the software tool used for nearly two thirds of the meta-analysis calculations contains serious errors that can dramatically underestimate confidence intervals (CIs), and this resulted in at least 1 spuriously statistically significant result. Despite the publication of statements and commentaries querying the reliability of the findings,[2-6] this faulty study now forms the evidentiary basis for an American College of Obstetricians and Gynecologists Committee Opinion,[7] meaning that its results are being presented to expectant parents as the state-of-the-art in home birth safety research.
In this article we describe in detail numerous mistakes in design, methodology, and reporting in the Wax meta-analysis that place clinicians and patients at risk for being misinformed.

Paradoxical Results

The main conclusion of the analysis by Wax and coworkers that planned home and planned hospital births exhibit similar perinatal mortality rates, but home births are characterized by 2-3 times higher neonatal death rates,[1] is drawn from data that are self contradictory. The mortality rates reported in the paper are reproduced in Table 1. CIs for these proportions were not provided in the article.Table 1: Perinatal and Neonatal Death Rates Reported by Wax and Colleagues

Planned Home Birth (%)

Planned Hospital Birth (%)

Perinatal death

All

0.07

0.08

Nonanomalous

0.07

0.08

Neonatal death

All

0.20

0.09

Nonanomalous

0.15

0.04

Adapted from Wax JR, et al. Am J Obstet Gynecol. 2010;203:243:e1-e8.[1]
Wax and colleagues defined perinatal death as stillbirth of at least 20 weeks or 500 g, or death of a liveborn infant within 28 days of birth. Neonatal deaths are defined as deaths of liveborn infants within 28 days of delivery.[1] With the definitions chosen by these investigators, neonatal deaths are a subset of perinatal deaths. As can be seen in Table 1, however, the investigators' results show that for planned home births, the neonatal death rates are actually far higher than the corresponding perinatal death rates. According to the investigators' definitions, these results are impossible. This is not unique to the planned home birth statistics, and in fact the neonatal death rate for all hospital births is also greater than the corresponding perinatal death rate. These paradoxical results arise from the dramatic differences in outcomes among the included studies, as will be described. It is clear, however, that the perinatal and neonatal death results cannot possibly represent comparable populations.
Because the perinatal death statistics are drawn from more than 500,000 births, whereas the neonatal death statistics are drawn from fewer than 50,000 births (and for many other reasons described below), the neonatal death statistics in the study by Wax and colleagues cannot be defended.

Numerical Errors

The results of the meta-analysis are presented in 2 tables: (1) for maternal outcomes, and (2) for neonatal outcomes.[1] For each outcome, Wax and associates provided the number of studies used in the calculation for that outcome, the number of births reporting that outcome, the total number of births in the included studies, and the summary odds ratio (OR) and 95% CI for the OR. Lists of which studies were included for each of the outcomes were not originally provided but have subsequently been made available.[8]
In attempting to reproduce some of the results, we find numerous numerical errors. In Table 2, we reproduce Wax and colleagues' table of neonatal outcomes, adding a column indicating which studies were used for each. Numerical errors are evident in every row. Many of these errors are minor, but several are highly significant, off by factors of 2 or more. In 1 instance (all perinatal deaths), the number of included studies was even incorrect. For another (large for gestational age), essentially every number is wrong.Table 2. A Reproduction of the Neonatal Results Table
Many of the ORs and CIs have been calculated incorrectly. In some cases, this was the result of errors apparently made in the extraction of data from the original studies. For example, we point to the study of Pang and coworkers[14] from which, to obtain results found in the summary table, the investigators must have counted 13 nonanomalous neonatal deaths in the home birth group. However, from Table 4 in that paper, it is clear that only 12 deaths should have been included.
Another example of an error in data extraction is in the all neonatal deaths outcome, where, again to reproduce the results in the supplemental table, the study by Janssen and colleagues[15] must have included a neonatal death in the hospital group. The only hospital death mentioned in that report was a stillbirth, not a neonatal death.
A third example of incorrect data extraction may be found, again in the all neonatal death outcome. In the study by Koehler, Solomon, and Murphy,[13] from which Wax and coworkers apparently included no deaths, 1 of the home birth deaths fit the definition of neonatal death.
In all 3 of these cases, the studies should not have been included in these outcomes at all.
A fourth example of incorrect data extraction is found in the perineal laceration outcome for which, to reproduce the results in the summary table, the report by Janssen and colleagues[19] apparently included only first- and second-degree lacerations rather than all perineal lacerations.
Both the investigators and peer reviewers ought to have been concerned that the direction and magnitude of the ORs for a variety of outcomes were illogical. Examples include postdates, for which the occurrence frequencies of 2.1% and 2.2% make the provided OR of 1.87 seem very unlikely, and newborn ventilation, for which the frequencies of 3.7% and 4.7% similarly make the OR of 1.12 seem unlikely. Several of the denominators appearing in the tables should also have raised concerns. For example, large for gestational age and newborn ventilation both have denominators of 13,525 for the home birth groups, in the first case arising from 4 studies, but from only 3 studies in the other. The denominator 10,701 appears for hospital births for both postdates and newborn ventilation, arising from 3 studies in the first case and 4 studies in the other.

A Faulty Computational Tool

In the methods section of the article, Wax and coworkers state that the random effects analyses were performed with "an online meta-analysis calculator from the University of Pittsburgh (http://www.pitt.edu/~super1/lecture/lec1171/meta5.doc)." This is a mischaracterization. Visiting this Web address results in a download of a Microsoft® Word document containing an embedded spreadsheet. The file is distributed as part of an online course in epidemiology.
Close inspection of the spreadsheet (retrieved on January 28, 2011), however, reveals several serious errors within the spreadsheet. The consequences of these errors are that:

The CI provided most likely underestimates the true CI, often dramatically;

The summary OR is in general incorrect;

The results of the analysis can appear to provide a statistically significant positive or negative result when it should not (this has in fact occurred in Wax and colleagues' article in at least 1 outcome); and

The calculated results depend on the order in which the studies are entered into the spreadsheet.

These errors have been confirmed by the spreadsheet's creator.[20] Refer to the appendix for details.
This spreadsheet appears to have been used to calculate results for 13 of the 21 outcomes in the paper (the investigators fail to state whether it was used for electronic fetal monitoring, but it does appear to have been used). All of the results calculated on the basis of the spreadsheet are numerically incorrect.
The article contains at least 1 outcome for which the statistical significance of the result is incorrect as a result of using the spreadsheet. For perineal lacerations, the result of an OR of 0.76 (95% CI: 0.72-0.81) would have been an OR of 1.03 (95% CI: 0.70-1.51) if a correct computational tool had been used, and very different conclusions would be drawn for this outcome. The error in data extraction associated with this outcome does not alter the finding that the use of the spreadsheet results in the wrong conclusion being drawn. We have not attempted to reproduce most of the maternal outcome results, but we expect that similarly serious errors remain.

Selective and Mistaken Inclusion/Exclusion

A number of errors are apparent in the inclusion of studies. The inclusion of de Jonge and associates[17] in the all perinatal death statistic is erroneous, because that article plainly states that all children with congenital abnormalities were excluded. This study should not have been included in nonanomalous perinatal death statistics either, because the statistics provided include only intrapartum and neonatal deaths up to 7 days. This time period is strikingly different from Wax and colleagues' definition of perinatal death. This study, which contributes more than 95% of the births used for the perinatal death rates, therefore, does not provide data that are compatible with Wax and colleagues' definitions for those outcomes. It is unclear why Wax and colleagues chose to exclude this study from the calculations for neonatal mortality but include the study for perinatal mortality. If that study were removed from the calculations for the 2 outcomes for which it was erroneously included, the total number of births included in the meta-analysis would have been reduced from nearly 550,000 to just 65,000. This dramatic reduction in the size of the dataset would have significantly reduced the impact of any findings of the meta-analysis. On the other hand, if Wax and colleagues had defined perinatal death and neonatal death according to definitions used by de Jonge and associates,[17] the conclusions for these outcomes would have been quite different.
In addition, a statement in the text cites 6 of the studies[9,11,13-15,18] as examining neonatal deaths. This appears to mischaracterize 3[9,13,15] of these articles. One of these[15] makes clear that it does not provide neonatal death rates compatible with the authors' definition (see the footnote to Table 5 in that paper). This paper should not have been cited at this point in the text and should not have been included in the calculation.
The list of studies used for the nonanomalous neonatal death outcome included 6 of the 7 references from the all neonatal death outcome, dropping only the study by Janssen and colleagues.[15] It is truly remarkable that the Janssen study was included in the all neonatal death outcome rather than the nonanomalous neonatal death outcome, because it specifically excluded births of infants with congenital anomalies. This study was also included in the all perinatal death outcome, where, in addition to the fact that it excluded infants with congenital anomalies, the death statistics provided are incompatible with Wax's definition of perinatal death.
It appears that the study by Ackermann-Liebrich and colleagues[9] should not have been included in the neonatal death outcomes, because deaths reported in this study are referred to as perinatal death rates rather than neonatal death rates, and perinatal was not defined in that work. The study by Koehler and colleagues[13] similarly reports perinatal deaths (undefined) rather than neonatal deaths. Definitions of perinatal death vary dramatically. In fact in the United States, the National Vital Statistics Reports provide data using 2 different definitions of perinatal death rates:

In 2005, these 2 rates differed by a factor of 1.6 (6.64 vs 10.73 per 1000).[21]
The paper by Pang and coworkers,[14] on the other hand, presents a completely different problem for inclusion. This article, which alone provides more than half of the neonatal deaths but just one third of the births, suffers from a number of serious flaws and has been thoroughly critiqued elsewhere.[22] One principal flaw is that it includes an unknown number of unplanned home births. Pang and colleagues[14] acknowledge this limitation of their study, and mention that previous studies show that neonatal mortality among unplanned home births is high, 73-120 per 1000 live births.
Pang and colleagues attempted to reduce the inclusion of unplanned home births by limiting data to uncomplicated pregnancies and deliveries of > 34 weeks' gestation with a midwife, nurse, or physician listed as attendant or certifier on the birth certificate. These criteria are an unreliable proxy for the true planning status; unplanned low-risk births would have been included by Pang and colleagues' criteria because many unplanned home births would have a physician, nurse attendant, or certifier.[22] According to Wax and colleagues, "An estimated 75% of low-risk singleton home births appear to be planned home deliveries."[1] This statement implies that about 25% of low-risk singleton home births in the United States are unplanned. One would expect then that as many as 1500 of the 6133 home births reported by Pang and colleagues[14] could have been unplanned. A further indication that unplanned home births are included in the study by Pang and colleagues is the fact that 7.6% of home births in that study were reported as having been attended by physicians, yet during the study period not a single physician in Washington state was known to offer home birth services.[22] Given that Wax and colleagues' stated goal is to compare outcomes of planned home vs planned hospital births, it is extraordinary and incomprehensible that the study by Pang and colleagues was included.
In summary, at least 4[9,13-15] of the 7 studies used to calculate the neonatal death outcomes appear to have been included inappropriately, and the vast majority of the births included in the perinatal death outcomes are from studies that did not provide statistics compatible with Wax and colleagues' definition of perinatal death.
Finally, it is surprising that the 2009 study by Janssen and colleagues[19] was not included in the nonanomalous perinatal death outcome, because it does appear to provide adequate information to be included in this row. Similarly, the study by Lindgren and colleagues[18] appears to provide adequate information to be included in both the all perinatal death and nonanomalous perinatal death outcomes. Koehler, Solomon, and Murphy[13] also describe perinatal mortality, although difficulties are associated with their definition of perinatal mortality.
In reviewing the 12 cited studies, we have found a variety of definitions of perinatal mortality and frequent omission of complete descriptions of which deaths are and are not reported. This issue would appear to make combining studies of perinatal mortality in any meaningful way to be very challenging. It is very surprising that Wax and associates did not mention this limitation at all.
With respect to other reported outcomes, we have not completed an exhaustive search for improperly included and excluded studies but have found some additional exclusions, for example, the study by Hutton, Reitsma, and Kaufman[12] and Janssen and colleagues' 2002 study[15] were not included in the perineal laceration outcome and the latter was also not included in the ≥ third-degree laceration outcome.
For a study in which the main results arise from distinctions between precisely defined categories, such as perinatal vs neonatal death and nonanomalous vs all newborns, the issue of improper inclusion/exclusion is of utmost importance, and we have described many specific examples where studies were included or excluded incorrectly.

More Methodological and Reporting Errors

Invalid Statistical Test

Wax and colleagues begin their discussion by remarking on the robustness of the neonatal death statistics, supported by the homogeneity of the observation across studies.[1] Homogeneity is said in the methods section to have been assessed with the Breslow-Day test. This test is not, however, valid for any of the perinatal or neonatal death outcomes. The user guide for SAS® 9.2 (SAS, Cary, NC), which the investigators claim to have used, states: "For the Breslow-Day test to be valid, the sample size should be relatively large in each stratum, and at least 80% of the expected cell counts should be greater than 5."[23] These criteria are not met for any of the mortality outcomes. The ORs for the individual, included studies range in some cases from 0 to infinity. It is not at all obvious that the studies are statistically homogeneous.

Association and Causation Conflated

Wax and colleagues claim that "less medical intervention during planned home birth is associated with a tripling of the neonatal mortality rate."[1] This is the sole conclusion offered in the abstract. Although it may be unintentional, the discussion in the paper implies that the reasons for an increase in neonatal mortality are derived from the studies that were included in the meta-analysis. However, the discussion of causes of neonatal mortality focuses on findings from studies that were not included in the meta-analysis, including studies that mix high-risk with low-risk cases.[24-27] Of the studies that are included in the meta-analysis, none associates rates of intervention with rates of neonatal mortality.
Any discussion of causation for elevated neonatal death rates for planned home births compared with planned hospital births is particularly specious in light of the paradoxical nature of the results it attempts to explain -- the results reproduced in Table 1 above. Furthermore, as part of their discussion of causation, Wax and colleagues claim that planned home births were characterized by a greater proportion of deaths attributed to respiratory distress and failed resuscitation. No data are provided in support of this claim, but 4[11,13,14,18] of the 12 primary articles are cited. However, not a single death in the home birth group in the study by Woodcock and associates[11] was attributed to respiratory distress or failed resuscitation. In the study by Lindgren and associates,[18] 1 of 2 home birth fatalities is attributed to asphyxia, whereas 4 of 7 in the hospital group list asphyxia in the cause of death. Koehler, Solomon, and Murphy[13] reported 1 death of an infant who had no onset of spontaneous respiration; in this study, the hospital birth comparison group consisted of only 67 births with no deaths reported. It is very difficult to see how these 3 studies could be interpreted to support the claim made by Wax and colleagues.
The entire discussion of causation is further undermined by the numerous numerical errors, and issues of inclusion and exclusion described above.

Errors in the Abstract

The abstract states that the results revealed less frequent assisted newborn ventilation in planned home births. However, this is inconsistent with the body of the article, where the result is not statistically significant but trends towards increased frequency. The spuriously statistically significant result for perineal laceration produced by the faulty spreadsheet results in another outcome that is incorrectly reported in the abstract. Significant additional errors in the abstract are associated with the mistaken inclusion/exclusion issues already described.

Shifting Numbers

Following a post-publication investigation of the study initiated by the American Journal of Obstetrics and Gynecology,[28] Wax published a supplement containing forest plots and summary tables.[8] The summary ORs and CIs for 3 of the reported outcomes (nonanomalous neonatal death, postdates, and prematurity) differ from their values in the originally published paper. Although none of these changes alters the direction of the reported result or its statistical significance, it is very surprising that Wax made no mention of these changes. None of the 3 updated outcomes yet provides correct values; for postdates and prematurity the faulty calculator was used, whereas the nonanomalous neonatal death outcome suffers from data extraction and mistaken inclusion errors.

Differences Among Studies

The group of studies included in this meta-analysis presents a number of additional statistical problems. Most, but not all, of the studies restricted inclusion to low-risk births. Most (by population), but not all, of the studies restricted home births to those attended by certified or licensed midwives. Most (by population), but not all, of the studies included only midwives operating in jurisdictions where midwives offering home birth services are well integrated into the greater healthcare system. All but a single study restricted home births to those that were planned.
Wax and coworkers make little mention of any of these complications, and it would seem that any conclusions made on the basis of combined results from such a disparate set of conditions would not be relevant to any parent planning a birth. Given these complexities, decisions would be better made on the basis of the subset of studies that are relevant to the conditions at hand.

Conclusion

The debate over the safety of home birth is deeply divided and emotionally charged. Reliable information is required to allow productive debate and informed decisions. In an era of evidence-based medicine, it is incomprehensible that medical society opinion can be formulated on research that does not hold to the most basic standards of methodological rigor.Appendix. An Analysis of "Meta5.doc," The Computational Tool Used For Random-Effects Meta-Analysis
The random effects calculations in the study by Wax and colleagues made use of a meta-analysis calculator implemented in a spreadsheet that was embedded in a Microsoft® Word document.{1} The spreadsheet is based upon formulae found in Petitti's meta-analysis text.{2} The formulae in question are in Table 7-7 on page 102 and on pages 116-117.
Specifically, the errors in the spreadsheet are:

In cell W10, which contains Petitti's D value (Δ2 in DerSimonian and Laird's notation{3}), any negative value for D should be replaced with 0. The spreadsheet, however, contained no logic to replace negative values. In cases where D is negative, this could dramatically alter the weightings of the datasets.

In the calculation of the adjusted weights (wi*), which should be given by wi* = 1/(D+(1/wi)), the spreadsheet cell reference to the cell containing D was entered not as an absolute cell reference (eg $W$10) but as a relative cell reference (W10), so that it referred to the (possibly incorrect, due to error 1) D value in cell W10, for only the first study. For subsequent studies, the value taken to be D was whatever value happened to be in cells W11, W12, W13, etc. As a consequence of the layout of the spreadsheet, those cells are generally blank, returning values of 0.

In the calculation of the CI limits, rather than employing the sum of the adjusted variances (variances*), the sum of the raw variances was used. To correct this, the references to cell H10 in cells I10 and J10 should be replaced by 1/sqrt(U14).

The spreadsheet provides a negative value for the Q statistic. Because Q is a weighted sum-of-squares, this cannot be correct. Q should have been taken from cell S14.

It is possible that the spreadsheet will be corrected. The original version of the spreadsheet can be found on the Internet archive "Wayback Machine."
After making the described corrections, the spreadsheet appears to implement correctly Petitti's description of the DerSimonian-Laird method. However, the results provided by the spreadsheet still show minor deviations from their expected values. This is the result of a discrepancy between Petitti's algorithm and DerSimonian and Laird's paper. In particular, Petitti makes use of the Mantel-Haenszel variance and OR in calculating the adjusted weights wi*. These do not appear to agree with the variance (si2) and weighted (natural log of) OR (yw) indicated for OR calculations in DerSimonian and Laird's original paper.
As an example of the possible consequences of using the spreadsheet, we consider a random effects model calculation combining the 2 datasets shown below.

Disease(exposed)

Disease(nonexposed)

Nondiseased(exposed)

Nondiseased(nonexposed)

Study 1

920

480

1216

1588

Study 2

160

172

235

157

The spreadsheet provides a random effects OR of 0.64, with 95% confidence bounds of 0.55-0.73. Simply exchanging the order of the 2 studies changes the result to OR = 2.48 (95% CI, 2.15-2.85).
The correct results from a DerSimonian-Laird random effects calculation{1} is OR, 1.26 (95% CI, 0.32-4.92). The correct results in this example were calculated using the rmeta package{4} for the R statistical analysis environment{5} and verified by hand calculations.
These analyses are shown in the forest plot in the Figure. Clearly, either of the 2 incorrect results (shown in blue and red) would lead to incorrect conclusions -- both results spuriously suggest statistical significance, although the conclusion on the direction of the effect depends on the order in which the studies are entered into the spreadsheet.Figure. Forest plot showing ORs and CIs for a random-effects meta-analysis of the example data sets. The correct result is represented by the long thin black diamond. The red and blue diamonds represent the 2 possible incorrect results produced by the faulty spreadsheet.References

Gyte G, Newburn M, Mcfarlane A. Critique of a meta-analysis by Wax and colleagues which has claimed that there is a three-times greater risk of neonatal death among babies without congenital anomalies planned to be born at home. July 7, 2010. Available at: http://www.scribd.com/doc/34065092/Critique-of-a-meta-analysis-by-Wax Accessed March 28, 2011.

American College of Nurse-Midwives. The American College of Nurse-Midwives expresses concerns with recent AJOG publication on home birth. Available at: http://www.medscape.com/viewarticle/725382 Accessed March 28, 2011.